Besides its roles in leukocyte adhesion to endothelial cells during inflammation, E-selectin has recently been shown to be involved in capillary tube formation, which is the critical for solid tumor growth, metastasis, and many angiogenic diseases. Identifying specific E-selectin ligands on endothelial cells is very important to understand this process. In this proposed research project, specific E-selectin glycoprotein ligands will be isolated from bovine capillary endothelial (BCE) cells using E-selectin-IgG protein A Sepharose. The N-terminal and internal peptide sequences will be determined. The cDNA encoding this novel E-selectin ligand will be cloned from a cDNA library prepared from BCE cells induced to form capillary tubes.The cDNA clone will be characterized by database searching, Northern and Southern blotting analysis. A soluble form of the identified E-selectin ligand will be expressed and antibodies specific to this E-selectin ligand will be raised. The soluble form of this novel E-selectin ligand and antibodies specific to this ligand are expected to have high potentials in the development of treatments of solid tumor growth, metastasis, and angiogenic diseases.